Y strainers are used to capture particulate matter in piping systems. They are so named due to their Y shaped configuration. Y strainers have also been referred to as Y “filters”. Whether a label of a Y “strainer” or Y “filter” is given to the device depends upon aperture size. As a general rule, Y devices which only are capable of capturing contaminants larger than 200 microns are termed “strainers” and Y devices apertures which are capable of capturing contaminants smaller than 200 microns are terms “filters”. For the purpose of this paper, no such distinction will be made and the term of Y strainer will be used in its broader more inclusive sense to denote the configuration.
When a hydrocarbon producing well has a sand problem, there are known sand separators that can be placed on the well. These sand separators are expensive units costing over $100,000.00 and are, therefore, only placed on wells that clearly have a long term, as opposed to a temporary sand problem.
When formation conditions are appropriate, hydrocarbon producing wells are stimulated by fracturing the formation with sand, a technique known as “fracing”. For this fracing procedure, very fine abrasive sand is used. Problems are being experienced with some of this fine abrasive sand appearing, without warning, in well production. The problem is not apparent until it manifests itself and sand starts appearing in the equipment. When it occurs, it can be difficult to determine whether the formation is merely “burping” small amounts of sand periodically or whether there is a more serious sand problem requiring a sand separator. The problem cannot be ignored. Even when present in small quantities, sand can damage equipment. When present in larger quantities, abrasive sand can wear through pipes and cause serious problems resulting in leakage into the environment and the threatening the lives of oil field workers.
Attempts have been made to use Y strainers until the magnitude of any sand problem can be determined. These attempts have been unsuccessful. The Y strainers presently available are not able to deal with the fine abrasive sand. There will now be described a method that was used to make the Y strainer more efficient in dealing with fine sand and a form of Y strainer that was built in accordance with the teachings of the method.